[media] uvcvideo: Add VIDIOC_[GS]_PRIORITY support

Signed-off-by: Laurent Pinchart <laurent.pinchart@ideasonboard.com>
Acked-by: Hans Verkuil <hans.verkuil@cisco.com>
Signed-off-by: Mauro Carvalho Chehab <mchehab@redhat.com>

drivers/media/usb/uvc/uvcvideo.h

@@ -372,6 +372,7 @@ struct uvc_video_chain {
 
 	struct mutex ctrl_mutex;		/* Protects ctrl.info */
 
+	struct v4l2_prio_state prio;		/* V4L2 priority state */
 	u32 caps;				/* V4L2 chain-wide caps */
 };